The anterior lumbar interbody fusion is similar to the posterior lumbar interbody fusion (PLIF), except that in ALIF, the disc space is fused by approaching the spine through the abdomen instead of through the lower back. Over the course of about 2 hours, the surgeon will perform the following initial steps.

• Making the incision. A 3-inch to 5-inch vertical incision is made in the lower abdomen, just left of the line from the pubic area to the belly button.
• Accessing the peritoneum. Layers of fat and muscle must be crossed to reach the peritoneum, which is a large sack that holds the internal organs in place.

There are 2 ways to achieve access to the front of the spine.

1. The transperitoneal is an approach that may be used when fusing the L4-L5 or L5-S1 segments. This approach may be preferred for surgical patients who are obese. In this procedure, the fat layer is dissected until the peritoneal membrane is accessed. The forceps lift the fat layer, taking the peritoneal membrane with it. This method is designed to gently separate the peritoneal membrane from the internal organs.5
2. The retroperitoneal approach tends to be the most common method because it may be used in the fusion of any of the lumbar spine segments. Conventionally, this method involves cutting the topmost muscular layer (the external oblique abdominal muscle) along the fibers and cauterizing the remaining layers.

Another emerging alternative involves splitting all 3 layers of abdominal muscle (the external oblique, internal oblique, and transverse muscles) along the fibers to reach the spine

The remaining steps include:

• Retracting the peritoneum. The peritoneum can be retracted to the side, allowing the spine surgeon access to the front of the spine without actually entering the abdomen.
• Retracting blood vessels. On top of the spine lay large blood vessels that continue to the legs. Many spine surgeons will perform this surgery together with a vascular surgeon, who mobilizes these large blood vessels.
• Replacing the disc with the bone graft. After the blood vessels have been moved aside, the disc material is removed and bone grafts or anterior interbody cages with bone graft are inserted. Another incision may be needed from the back to help fixate the devices. Pedicle screws, which always accompany PLIF surgery, may be optional during ALIF surgery.

Patients typically stay in the hospital for 1 night, sometimes 2 nights, and then return home. A full recovery plan will be recommended and usually focuses on rehabilitation for the 6- to 12-week period following the surgery.

The fusion process for the bones does not occur during the surgery itself; instead, the surgery sets up the environment for the bones to fuse and over the following months (up to 12 months) the fusion gradually takes place. It is important to schedule follow-up appointments to evaluate the progress of the fusion.

The fusion process for the bones does not occur during the surgery itself; instead, the surgery sets up the environment for the bones to fuse and over the following months (up to 12 months) the fusion gradually takes place. It is important to schedule follow-up appointments to evaluate the progress of the fusion.